Rodriguez posted a statement on his website Tuesday night.
"In recent weeks, following dialogue with caring friends and players, both Dominican and American, I reached the conclusion that if I played in the Classic, I would play for the United States and honour my American citizenship.
"I appreciate the support and understanding of my fellow Dominican players and friends who aided me in making this decision.
Yankees third baseman Alex Rodriguez will play for the U.S. at the World Baseball Classic. (AP Photo)
"The World Baseball Classic offers baseball and its fans an exciting new forum and I look forward, if selected, to representing the United States in what will be baseball's greatest international competition."
Because Rodriguez was born in New York and has Dominican parents, he was eligible to play for either country.
Last year, the 30-year-old Rodriguez batted .321 with 48 homers and 130 RBIs in his second season with New York. Rodriguez became the first Yankee honoured as MVP since Don Mattingly in 1985.
Other top U.S. players announced included San Francisco Giants slugger Barry Bonds, pitcher Roger Clemens and veteran outfielder Ken Griffey, Jr.
